Orlando, Florida -- Documents released Wednesday show tests could only identify George Zimmerman's DNA on the gun used to fatally shoot 17-year-old Trayvon Martin. Those tests could be a blow to Zimmerman's defense, since the former neighborhood watch volunteer has maintained he shot Martin after the teen reached for his gun.

What could help Zimmerman is a diagram released Wednesday from a witness who says they saw someone with a black shirt on top of a person with a red colored shirt.

Zimmerman was wearing a red jacket while Martin was wearing a dark gray sweatshirt the night of the shooting.

Zimmerman claims Martin was on top of him slamming his head into the sidewalk before he shot the teen.

Other items released Wednesday include a short interview with a 7-Eleven clerk who did not remember seeing Martin in the convenience store buying Skittles the night of the shooting.

Dozens of pictures of the gated community were also released as well as e-mails sent to the former Sanford police chief in the days following Martin's death.

So far no trial date has been set in the case while Zimmerman remains free on bond.